Instruments for measuring and recording electric power parameters, such as power flow and power disturbance parameters, are well known in the art. Such instruments typically connect to electric power voltage and current signals, then either compare those signals to thresholds that have been programmed for various types of well-known power disturbance events, such as harmonics, voltage swells and sags, imbalance, power failures, waveshape faults, impulses, frequency variations, flicker, and high frequency noise, or mathematically process those signals to extract power flow parameters. When a triggering event occurs, such as a power disturbance event or an..elapsed interval of time, these well-known instruments generate an alarm or report. The alarm or report may consist of a indicator on the instrument itself, or a printed or displayed report at the instrument.
For at least twenty years, attempts have been made to make the reports of such power parameter recording instruments sufficiently easy to interpret that no special training in their interpretation would be required, and attempts have been made to make those reports available at convenient locations, which are typically located at some distance from electric power system being measured.
Despite all these efforts, a power recording instrument that requires essentially no user training has remained elusive.
Early power disturbance instruments, such as that disclosed by Smith in 1974 in U.S. Pat. No. 3,813,667, presented reports that consisted of electro-mechanical counters, and provided a remote alarm external voltage that could, for example, ring an alarm bell at a remote location. Skilled interpretation of the meaning of numbers shown on the electro-mechanical counters was required.
Subsequent power disturbance monitors, such as the Model 606 manufactured by Dranetz Technologies of Edison, N.J., beginning in the mid-1970's, made-interpretation of reports somewhat easier by providing a printed tape that showed the time, date, amplitude, and type of disturbance. Skilled interpretation was still required; special training courses were offered on interpreting these printed tapes.
In the early 1980's, power disturbance monitors with simple latched alarm indicators, such as the Model GS-1 manufactured by Basic Measuring Instruments of Santa Clara, Calif., became available. Although less skill was required to interpret these indicators than the printed tapes of other power disturbance monitors, less information was available as well; the user could not tell when a disturbance occurred, or how many occurred. The information was available only at the site where the instrument was installed; no remote communication was possible.
In the middle 1980's, power disturbance monitors were developed that provided a graphic representation of power disturbances, such as those disclosed by McEachern et al. in U.S. Pat. Nos. 4,642,563 and 4,694,402. These graphic monitors were intuitively easier to interpret than printed text, at least for technically skilled users. But special interpretation training was still required. As of the date of this application, graphic power disturbance monitors represent the state of the art. Considerable training and expertise is required to interpret the reports of such graphic power disturbance monitors. Indeed, several organizations offer well-attended classes taught by experts in interpreting the results of such graphic power disturbance monitors.
In addition to local notification, the alarm or report generated by such instruments may also be transmitted by telephone. It is well-known in the art to construct power parameter monitoring instruments that couple to a telephone line, and that dial a pre-programmed number whenever a power disturbance event occurs. Such instruments are widely available from Basic Measuring Instruments of Santa Clara, Calif.; Dranetz Technologies of Edison, N.J.; and many other suppliers. All such instruments are designed to communicate through the standard telephone system with a computer or computer-based system. Such instruments are usually also capable of answering an incoming call; again, all such instruments expect the incoming call to be originated by a computer or a computer-based system.
It is often difficult to obtain a telephone line for such an instrument. Typically, these systems make and receive only a few calls per month, and it may be difficult to economically justify installing a telephone line for so few calls.
Due to the requirements described above for expertise in interpreting the reports from power disturbance monitors, it is typical industry practice for such instruments to be controlled and used by technically skilled individuals, such as power quality engineers and utility field technicians. These individuals typically have access to, and are comfortable with, the computer-based systems required to communicate with such instruments. But, as competition between electric utilities increases, it is frequently a marketing executive or another user with minimal technical training, not a power quality engineer, who needs immediate information about power quality events at a utility customer. Such an individual is often more comfortable with pagers and voice-mail systems than he or she is with computer-based programming.
Attempts to make the prior-art computer-based systems sufficiently friendly for wide-spread use by utility marketing executives, for example, have not achieved commercial success.
Speech-synthesis systems, which allow microcomputer-based devices to generate synthetic human speech signals, are well known in the art. Such systems frequently form the basis for interacting with voice-mail systems, for example.
Despite the wide-spread use of power disturbance measuring instruments, and despite the wide-spread connection of such instruments to telephone systems, the prior art does not teach employment of speech synthesis for remote communication with such instruments.
This invention provides a novel combination of well-known power parameter measuring and recording technology with well-known speech synthesis technology. It further combines a novel technology for sharing a phone line with other users.
This invention succeeds in making a sufficiently easy-to-use system for wide-spread use by minimally trained users where other approaches have failed.
The combination provides an unexpected result in that consumers of electric power, who typically have even less knowledge than utility executives about electric power, find the invention sufficiently easy to use that they can check on recorded power parameters themselves. For example, a typical consumer who has access to this invention can check whether a suspected power quality disturbance event did in fact take place without even contacting his or her utility supplier.